// 实现这个项目的构建任务
const { src, dest, watch, parallel, series } = require('gulp');
const browserSync = require('browser-sync');
const loadPlugins = require('gulp-load-plugins');
const del = require('del')
const swig = require('gulp-swig');

const plugins = loadPlugins();
const bs = browserSync.create();

const data = {
  menus: [
    {
      name: 'Home',
      icon: 'aperture',
      link: 'index.html'
    },
    {
      name: 'Features',
      link: 'features.html'
    },
    {
      name: 'About',
      link: 'about.html'
    },
    {
      name: 'Contact',
      link: '#',
      children: [
        {
          name: 'Twitter',
          link: 'https://twitter.com'
        },
        {
          name: 'About',
          link: 'https://www.baidu.com'
        },
        {
          name: 'divider'
        }
      ]
    }
  ],
  pkg: require('./package.json'),
  date: new Date()
}

const clean = () => {
  return del(['dist', 'temp']);
}

const style = () => {
  return src('src/assets/styles/*.scss', { base: 'src' })
    .pipe(plugins.sass({outputStyle: 'expanded'}))
    .pipe(dest('temp'))
    .pipe(bs.reload({stream: true}))
}

const script = () => {
  return src('src/assets/scripts/*.js', { base: 'src' })
    .pipe(plugins.babel({ presets: ['@babel/preset-env'] }))
    .pipe(dest('temp'))
    .pipe(bs.reload({ stream: true }))
}

// const page = () => {
//   return src('src/*.html', { base: 'src' })
//     .pipe(plugins.swig({ data }))
//     .pipe(dest('temp'))
//     .pipe(bs.reload({ stream: true }))
// }

const page = () => {
  return src('src/*.html', { base: 'src' })
    .pipe(swig({ data }))
    .pipe(dest('temp'))
    .pipe(bs.reload({ stream: true }))
}

const image = () => {
  return src('src/assets/images/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('temp'));
}

const font = () => {
  return src('src/assets/fonts/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

 const extra = () => {
  return src('public/**', { base: 'public' })
    .pipe(dest('dist'))
 }

 const serve = () => {
  watch('src/assets/styles/*.scss', style);
  watch('src/assets/scripts/*.js', script);
  watch('src/*.html', page);
  watch([
    'src/assets/images/**',
    'src/assets/fonts/**',
    'public/**'
  ], bs.reload)

  bs.init({
    notify: false,
    port: 2020,
    server: {
      baseDir: ['temp', 'src', 'public'],
      routes: {
        '/node_modules': 'node_modules'
      }
    }
  })
 }

 const useref = () => {
  return src('temp/*.html', { base: 'temp' })
    .pipe(plugins.useref({ searchPath: ['temp', '.'] }))
    .pipe(plugins.if(/\.js$/, plugins.uglify()))
    .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
    .pipe(plugins.if(/\.html/, plugins.htmlmin({
      collapseWhitespace: true,
      minifyCSS: true,
      minifyJS: true
    })))
    .pipe(dest('dist'))
 }

 const compile = parallel(style, script, page);

 const build = series(
   clean, 
   parallel(
     series(compile, useref),
     image,
     font,
     extra
    ))

 const develop = series(compile, serve);

 module.exports = {
   clean,
   compile,
   build,
   develop,
   useref
 }